846 research outputs found
Experimental Results of a Differential Angle-of-Arrival Based 2D Localization Method Using Signals of Opportunity
This paper presents a study of differential AoA (Angle-of-Arrival) based 2D localization method utilizing FM radio signals
(88 MHz–108 MHz) as Signals of Opportunity (SOP). Given prior knowledge of the transmitters’ position and signal characteristics,
the proposed technique utilizes triangulation to localize receiver’s 2D position. Dual antenna interferometry provides the received
signals’ AoA required for triangulation. Reliance on precise knowledge of antenna system’s orientation is removed by utilizing
diferential Angle of Arrivals (dAoAs). Te 2D localization accuracy is improved by utilizing colocated transmitters, a concept
proposed in this paper as supertowers. Analysis, simulation, and ground-based experiments have been presented; results showed
that when the SNR (Signal-to-Noise Ratio) is higher than 45 dB, the proposed method localizes the receiver’s 2D position with an
error of less than 15 m
Are we teaching our students what they need to know about ageing? Results from the National Survey of Undergraduate Teaching in Ageing and Geriatric Medicine
Introduction - Learning about ageing and the appropriate management of older patients is important for all doctors. This survey set out to evaluate what medical undergraduates in the UK are taught about ageing and geriatric medicine and how this teaching is delivered.
Methods – An electronic questionnaire was developed and sent to the 28/31 UK medical schools which agreed to participate.
Results – Full responses were received from 17 schools. 8/21 learning objectives were recorded as taught, and none were examined, across every school surveyed. Elder abuse and terminology and classification of health were taught in only 8/17 and 2/17 schools respectively. Pressure ulcers were taught about in 14/17 schools but taught formally in only 7 of these and examined in only 9. With regard to bio- and socio- gerontology, only 9/17 schools reported teaching in social ageing, 7/17 in cellular ageing and 9/17 in the physiology of ageing.
Discussion – Even allowing for the suboptimal response rate, this study presents significant cause for concern with UK undergraduate education related to ageing. The failure to teach comprehensively on elder abuse and pressure sores, in particular, may be significantly to the detriment of older patients
Trouble with the Lorentz law of force: Incompatibility with special relativity and momentum conservation
The Lorentz law of force is the fifth pillar of classical electrodynamics,
the other four being Maxwell's macroscopic equations. The Lorentz law is the
universal expression of the force exerted by electromagnetic fields on a volume
containing a distribution of electrical charges and currents. If electric and
magnetic dipoles also happen to be present in a material medium, they are
traditionally treated by expressing the corresponding polarization and
magnetization distributions in terms of bound-charge and bound-current
densities, which are subsequently added to free-charge and free-current
densities, respectively. In this way, Maxwell's macroscopic equations are
reduced to his microscopic equations, and the Lorentz law is expected to
provide a precise expression of the electromagnetic force density on material
bodies at all points in space and time. This paper presents incontrovertible
theoretical evidence of the incompatibility of the Lorentz law with the
fundamental tenets of special relativity. We argue that the Lorentz law must be
abandoned in favor of a more general expression of the electromagnetic force
density, such as the one discovered by A. Einstein and J. Laub in 1908. Not
only is the Einstein-Laub formula consistent with special relativity, it also
solves the long-standing problem of "hidden momentum" in classical
electrodynamics.Comment: 7 pages, 1 figur
Joint Comprehensive Plan of Action Opportunity for HIF in Iran
Cooperation in fusion energy research and
high-energy accelerators has been a “bridge over
troubled waters” for most of a century. Physics
research has traditionally been an international
endeavor, involving the earliest accelerator
developments, and hitting a hiatus only during
World War II. Fusion energy research using
magnetic confinement was internationalized by
the Geneva meeting in 1958. Iran is and has been
a participant in fusion research, even during the
troubles of the past couple decades..
Joint Comprehensive Plan of Action Opportunity for HIF in Iran
Cooperation in fusion energy research and
high-energy accelerators has been a “bridge over
troubled waters” for most of a century. Physics
research has traditionally been an international
endeavor, involving the earliest accelerator
developments, and hitting a hiatus only during
World War II. Fusion energy research using
magnetic confinement was internationalized by
the Geneva meeting in 1958. Iran is and has been
a participant in fusion research, even during the
troubles of the past couple decades..
Eyelid Cosmetic Enhancements and Their Associated Ocular Adverse Effects
Numerous cosmetic enhancements and augmentations to the natural appearance of the periorbital area are readily available today. Due to the increasing popularity of these cosmetic procedures, it is important for ophthalmologists to be aware of their potential risks, complications and adverse effects. The aim of this literature review was to introduce some of the most common ocular cosmetic enhancements and provide a comprehensive overview of their associated adverse effects reported in various medical journals. PubMed, Embase, and Google Scholar were used to identify articles related to the following ocular cosmetic procedures; eyelash extensions, permanent eyelid tattooing, and eyelash dyeing. The most common complication associated with eyelash extensions was allergic blepharitis (79%). Allergic granulomatous reactions were the predominant complication in patients who underwent eyelid tattooing (56%). Besides, 60% of subjects who underwent eyelash dyeing experienced allergic contact dermatitis as the most common adverse effect. Although millions of these procedures are performed annually without any adverse effects, reports of complications continue to increase in the literature. Knowledge of the possible adverse effects associated with these enhancements is important for eye care providers and licensed estheticians to be aware of given both the direct and indirect effects they may have on ocular health and visual outcomes
Eyelid Cosmetic Enhancements and Their Associated Ocular Adverse Effects
Numerous cosmetic enhancements and augmentations to the natural appearance of the periorbital area are readily available today. Due to the increasing popularity of these cosmetic procedures, it is important for ophthalmologists to be aware of their potential risks, complications and adverse effects. The aim of this literature review was to introduce some of the most common ocular cosmetic enhancements and provide a comprehensive overview of their associated adverse effects reported in various medical journals. PubMed, Embase, and Google Scholar were used to identify articles related to the following ocular cosmetic procedures; eyelash extensions, permanent eyelid tattooing, and eyelash dyeing. The most common complication associated with eyelash extensions was allergic blepharitis (79%). Allergic granulomatous reactions were the predominant complication in patients who underwent eyelid tattooing (56%). Besides, 60% of subjects who underwent eyelash dyeing experienced allergic contact dermatitis as the most common adverse effect. Although millions of these procedures are performed annually without any adverse effects, reports of complications continue to increase in the literature. Knowledge of the possible adverse effects associated with these enhancements is important for eye care providers and licensed estheticians to be aware of given both the direct and indirect effects they may have on ocular health and visual outcomes
The prevalence of sarcopenia in fallers and those at risk of falls in a secondary care falls unit as measured by bioimpedance analysis
Objectives: Sarcopenia is characterised by loss of skeletal muscle mass and strength with adverse outcomes: physical disability, poor quality of life and death. Low muscle mass and strength are risk factors for falls, although there are few data available on the prevalence of sarcopenia in fallers. This study aimed to determine prevalence of sarcopenia in older people referred to a falls clinic. /
Methods: Consecutive patients referred to a secondary care falls unit were recruited. Sarcopenia was diagnosed using the European Working Group on Sarcopenia definition (low muscle mass and function) and cut-off points. Bio-impedance measured appendicular skeletal muscle mass. Gait speed and grip strength were functional measures. /
Results: Fifty-eight patients were recruited. Mean (SD) grip strength for women and men respectively were 17.9 (4.9) and 29.9(8.7) kg, mean (SD) gait speeds were 0.61(0.18) and 0.72 (0.4) m/s, mean (SD) appendicular skeletal muscle index in women and men were 6.98(1.0) and 7.85 (1.0) kg/m2 (p=0.018). Prevalence of sarcopenia was 9.8% (95% CI=1.6%-18%). /
Conclusions: Sarcopenia, as measured by bio-impedance is not uncommon in older people accessing a secondary care falls clinic. Bio-impedance was simple to perform, although further validation against gold standard methods is needed. As nutritional and exercise interventions for sarcopenia are available, simple methods for diagnosing sarcopenia in fallers should be considered
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